In present capacitive touch sensors the position of the touch by a finger or stylus is determined as a function of the current flow at the capacitive contact point. See for example U.S. Pat. Nos. 4,071,691, 4,129,747, 4,198,539, 4,293,734, 4,302,011, 4,371,746, 4,430,917. However, stray capacitance, as for example the capacitance introduced by the placement of the user's free hand on or near the sensor or its periphery, such as on the bezel, causes the system to determine the touch points as the average position between the two locations, as a function, for example, of the relative current flows. In one attempt to overcome this problem the stray capacitance is sensed periodically and provided to the detection circuit which can then compensate for it. However, this solution is not satisfactory. For while the stray capacitance of the free hand of the user, left in place on the bezel, can be compensated for in this way, that stray capacitance is not predictable at the critical moment. That is, when the user touches the sensor with a finger of the other hand the stray capacitance introduced by the free hand readjusts in the manner of a bridge circuit so the real value of the stray capacitance changes. Further, the sensed level of stray capacitance constitutes a bias which subtracts from the overall dynamic range of the system. Other attempts to address the stray capacitance problem have used sophisticated signal processing and software techniques, but these approaches are complicated and compensate for the problem rather than seek to eliminate it at its source.